So just bought a 26 nosler and got reloading gear. Just tried to bump the shoulder on my first fire formed brass. Case grows in oal length but measurement with comparator does not show any movement. Die is fully bottomed out on shell holder. Brass chambers in rifle however the once fired does as well...has it just not fully expanded to the chamber? Using nosler trophy grade ammo.
Head space 26 nosler
- Thread starter dru
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- Western Manitoba
You are describing that the neck lengthened, even though the shoulders did not move forward. So, trim to length and carry on. I do not see what you describe as a problem, although others might know something I have missed??
Expecting to see the shoulder bumped back however the die doesn't seem to be capable of moving it any further. Brass is still less than trim length. Its a hunting rifle and don't want to end up in a situation where I cannot chamber a round in the field.
- Location
- Western Manitoba
I am still not seeing how you have a problem - if your re-sized brass chambers now, it will chamber in the field, unless your loading process swells up the neck or something like that. I suspect that the "shoulder bumped back" is only a thing when your fired cases are tight to close the bolt on - maybe in a couple more firings? The 26 Nosler is NOT a belted case, so later, if you find a need to do so, can have .002" or so removed off the top of your shell holder, or, for almost all that I have used, it is easiest to slide a .002" or .003" feeler gauge under the case head while it is in the shell holder - either way will allow the case to go into the die about that .002" or so more than it does now. From what you are describing, I think you have a sizing die set-up that is a good match for your chamber?
What type press are you using?
Is the die adjusted 1/8 to 1/4 turn past contact with the shell holder with press cam over?
If you look at the image below you will see that your die did push the shoulder back after it was squeezed forward. The real question is if the shoulder needs pushed back a smidgen more.
I think if the die was lowered with more cam over you would see the shoulder pushed back a few thousandths more. On the plus side, you will not have to worry about bumping the shoulder back too far and have case head separations. And if needed you could lap the top of the shell holder a few thousandths to increase your shoulder bump.
If you had just neck sized the cases you would not be asking your question. And you would be thinking about how many times you could neck size only before the shoulder did need to be pushed back.
In the video below is your answer to the proper amount of shoulder bump by feel.
Is the die adjusted 1/8 to 1/4 turn past contact with the shell holder with press cam over?
If you look at the image below you will see that your die did push the shoulder back after it was squeezed forward. The real question is if the shoulder needs pushed back a smidgen more.
I think if the die was lowered with more cam over you would see the shoulder pushed back a few thousandths more. On the plus side, you will not have to worry about bumping the shoulder back too far and have case head separations. And if needed you could lap the top of the shell holder a few thousandths to increase your shoulder bump.
If you had just neck sized the cases you would not be asking your question. And you would be thinking about how many times you could neck size only before the shoulder did need to be pushed back.
In the video below is your answer to the proper amount of shoulder bump by feel.
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- Location
- Western Manitoba
Not to "beat a dead horse" but you have not described a problem that needs a solution? If your re-sized brass chambers easily now, there is nothing to gain by bumping back the shoulder. Use your rifle - bolt and chamber - as your gauge - do not need or care what an intermediate measurement is saying - especially for a hunting rifle - it has to chamber, not "should" chamber or "might" chamber - so use the chamber as your guidance.
Was our practice as boys when learning from our Dad - morning of the deer hunt - every round (all were factory shells back then) got ran through the rifles - and we did find some that "stuttered" - bent, whatever - did not carry them with us - we screwed up enough ways on our own - did not need "Murphy's" help!
Was our practice as boys when learning from our Dad - morning of the deer hunt - every round (all were factory shells back then) got ran through the rifles - and we did find some that "stuttered" - bent, whatever - did not carry them with us - we screwed up enough ways on our own - did not need "Murphy's" help!
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- Location
- Western Manitoba
I helped an acquaintance that had a "custom" cut neck in a rifle chamber that he inherited from his GrandPa. Using "normal" brass, he had a very tight fit going into the chamber - basically no to negative clearance within the neck area. When he fired a nearly "Start" load, the bolt was a chore to open, a new bullet needed a lot of pressure to be forced into that fired neck and about half of the fired cases that he had would not allow the bolt to close, and none allowed an "easy" close. So the tight neck was significantly elevating the pressure in his rounds - and to use that brass again required a "shoulder bump" plus having the necks thinned. Oddly, the "shoulder bump" required nothing fancy - simply setting up the die so his press "cammed over" re-sized that brass so that it chambered easily. So the "shoulder bump" may be occurring already, as per previous posts.
You are experiencing what happens when you have a properly matched up Chamber, Cartridge and Sizing Die and a Factory Round that is not over pressure. Go to Saami and look up drawings of the 26 Nosler Minimum Chamber and Maximum Cartridge (Brass) and you will likely find that an unfired round is only about 0.005" under Saami Max cartridge at the neck, 0.003" under at the shoulder diameter and about 0.003" at the 0.200" Base datum. Head Space, with .420 Comparator Should be nearly the same on a new round as a fired round as you found with a FL sized round. I have measured 270 WSM ammo that stretched 0.008" at the case mouth, 0.014" at the shoulder diameter, 0.006" at the base datum and 0.008" HS. One of them came out looking like this:
As you can see the HS is measured at the Shoulder Datum, 0.420" on the 26 Nosler, and as you reduce the neck and shoulder diameter clearance is created and the HS measurement changes at the datum without moving the shoulder. In fact the shoulder datum measurement, on a FL sized case, can be longer than that of a fired case by a couple of thousands and still fit in your chamber so you have actually moved the shoulder datum back to a good fit. I have pictures of my 270 PHC, that illustrate this. First is a measurement of my "Go Gauge", at the 0.420" datum:
Brass formed just over "GO Gauge":
Brass fired 2X to chamber 150 LRAB at over 3100 fps and then 3085 fps accuracy node:
Brass FL sized to fit chamber:
As you can see there is no visible pressure ring , at the 0.200" Datum, because brass never stretches more than 0.002" inches which is 0.001" under Saami Maximum Cartridge dimension and 0.002" under Saami Minimum Chamber dimensions. Full Length dies only size the brass 0.0005" at the base datum and about 0.002" at the shoulder diameter so brass is worked at a very minimum and case trim length is almost non existent. If you load your 26 Nosler this way your brass will last a long time.
